A power conversion system (PCS) within a battery storage system inverts DC power output from batteries into AC power, which can then be exported to the grid. The PCS uses a digital signal processor (DSP) to manage the switching controls within an inverter power circuit. Example DSP circuits that operate as step wave power converters are described in U.S. Pat. Nos. 6,608,404 and 7,808,125 which are herein incorporated by reference in their entireties. These DSP circuits may use a feedback process where a measured power level is compared with a parameter setpoint. The setpoint may be manually set by a user or set through an energy management system (EMS).
A fundamental control parameter is the AC output power from the PCS. The PCS may perform a cycle-by-cycle calculation of the output voltage and current magnitudes of the battery output power. The calculated PCS power is then compared with the setpoint and the error is used to adjust power circuit switching. Output power from the PCS is often used for control feedback since the output power is directly tied to the functionality of the battery system (i.e., storing and exporting energy).